arpadveress 
You might get surprised that on the site you work for HOW is Ex managed.
In many cases all instrumentations are with Ex d because they had some issues previously with Ex i regarding lightning events even if protection was there. Or they use Ex d for JBs even if they know Ex e for motors.
If this is the case, you shall follow and it shall be communicated to you – site Ex documentation has again top priority. Then it works.
Keep up good work.
Arpad
